Injection site training system

ABSTRACT

An injection apparatus and training system for prophylactic, curative, therapeutic, acupuncture, or cosmetic injection training and certification. In an embodiment, an injection training system is described that includes a testing tool having a needle and a position sensor, where the position sensor is configured to obtain position information of the testing tool. The system also includes an injection apparatus configured to receive a simulated injection by the testing tool. The system includes a display device configured to receive the position information and to display position data reflective of the position information.

This application is a continuation of U.S. patent application Ser. No.15/886,363, filed Feb. 1, 2018, which is a continuation of U.S. patentapplication Ser. No. 14/598,614, filed Jan. 16, 2015, which claims thebenefit of U.S. Provisional Application No 61/928,915, filed on Jan. 17,2014, U.S. Provisional Application No 61/939,093, filed on Feb. 12,2014, and U.S. Provisional Application No. 62/066,792, filed on Oct. 21,2014, the entirety of each of which is hereby incorporated herein byreference.

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND

A variety of medical injection procedures are often performed inprophylactic, curative, therapeutic, or cosmetic treatments. Injectionsmay be administered in various locations on the body, such as under theconjunctiva, into arteries, bone marrow, the spine, the sternum, thepleural space of the chest region, the peritoneal cavity, joint spaces,and internal organs. Injections can also be helpful in administeringmedication directly into anatomic locations that are generating pain.These injections may be administered intravenously (through the vein),intramuscularly (into the muscle), intradermally (beneath the skin),subcutaneously (into the fatty layer of skin), or intraperitoneally(into the body cavity). Injections can be performed on humans as well ason animals. The methods of administering injections typically vary fordifferent procedures and may depend on the substance being injected,needle size, or area of injection.

Injections are not limited to treating medical conditions, but may beexpanded to treating aesthetic imperfections or restorative cosmeticprocedures. Many of these procedures are performed through injections ofvarious products into different parts of the body. The aesthetics andtherapeutic industry comprises two main categories of injectableproducts: neuromodulators and dermal fillers. The neuromodulatorindustry commonly uses nerve-inhibiting products such as Botox®,Dysport®, and Xeomin®. The dermal filler industry uses productsadministered by providers to patients for both cosmetic and therapeuticreasons, such as, for example, Juvederm®, Restylane®, Belotero®,Sculptra®, Artefill®, and others. These providers or injectors mayinclude plastic surgeons, facial plastic surgeons, oculoplasticsurgeons, dermatologists, nurse practitioners, dentists and nurses.

A problem in the administration of injections is that there is noofficial certification or training process. Anyone with a minimalmedically-related license may inject a patient. These “injectors” mayinclude primary care physicians, dentists, veterinarians, nursepractitioners, nurses, physician's assistants, or aesthetic spaphysicians. However, the qualifications and training requirements forinjectors vary by country, state, and county. For example, in moststates in the United States, the only requirement to be permitted toinject patients with neuromodulators and/or fillers is to have a nursingdegree or medical degree. Accordingly, there is a lack of uniformity andexpertise in administering such injections. The drawbacks with this lackof uniformity in training and expertise are widespread throughout themedical industry. Doctors and practitioners often are not well-trainedin administering injections of diagnostic, therapeutic, and cosmeticchemical substances. This lack of training has led to instances ofchronic pain, headaches, bruising, swelling, or bleeding in patients.

Current injection training options are classroom-based, with hands-ontraining performed on live models. The availability of models islimited. Moreover, even when available, live models are limited in thenumber and types of injections they may receive. The need for livemodels is restrictive because injectors are unable to be exposed to awide and diverse range of situations and anatomies in which to practice.For example, it may be difficult to find live models with different skintones or densities. This makes the training process less effectivebecause patients have diverse anatomical features as well as varyingprophylactic, curative, therapeutic, or cosmetic needs. Live models arealso restrictive because injectors are unable to practice injectionmethods on the internal organs of a live model due to safety and healthconsiderations.

As a result of these limited training scenarios, individuals seekingtreatments involving injections have a much higher risk of being treatedby an inexperienced injector. This may result in low patientsatisfaction with the results, or in failed procedures. In manyinstances, patients have experienced lumpiness from incorrect dermalfiller injections. Some failed procedures may result in irreversibleproblems and permanent damage to a patient's body. For example, patientshave experienced vision loss, direct injury to the globe of the eye, andbrain infarctions where injectors have incorrectly performed dermalfiller procedures. Additional examples of side effects includeinflammatory granuloma, skin necrosis, endophthalmitis,injectable-related vascular compromise, cellulitis, biofilm formation,subcutaneous nodules, fibrotic nodules, and other infections.

As a result of the varying qualifications and training requirements forinjectors, there is currently no standard to train, educate, and certifyproviders on the proper and accurate process of various injectiontechniques. Patients seeking injections also have few resources fordetermining the qualifications or experience of a care practitioner.

SUMMARY

The present disclosure generally relates to an injection apparatus andtraining system for prophylactic, curative, therapeutic, acupuncture, orcosmetic injection training and certification. The training systemeliminates the need to find live models for hands-on training sessions.The training system provides feedback on trainees and the accuracy ofinjection procedures performed. In an embodiment, feedback is providedin real time. The training system can be used as a measurement on howthe “trainee” is doing prior to receiving actual product by themanufacturing company as a measure of qualification. The training systemreduces the risks associated with inexperienced and uncertified medicalpersonnel performing injection procedures.

The training system can be used to educate, train, and certify medicalpersonnel for injection procedures. It can also be utilized as a testingprogram for certifying medical personnel. The system will enable usersto practice a variety of injections, ranging from on label to off labelproduct injections. In some embodiments, the system may allow users totrain for therapeutic treatments. In other embodiments, the system mayallow users to train for injections into arteries, bone marrow, thespine, the sternum, the pleural space of the chest region, theperitoneal cavity, joint spaces, internal organs, or any other injectionsites. The system may be used for any type of injection, including, butnot limited to those involving prophylactic, curative, therapeutic, orcosmetic treatments in both humans and animals. Illustratively, by wayof non-limiting example, the disclosed system may be used to simulate acosmetic application of filling of a wrinkle with a dermal filler. Inother applications, the systems disclosed herein can be used for dentalapplication and training for dental procedures.

In an aspect of the present disclosure, an injection training system isdescribed that includes a testing tool having a needle and a positionsensor, where the position sensor is configured to obtain positioninformation of the testing tool. The system also includes an injectionapparatus configured to receive a simulated injection by the testingtool. The system includes a display device configured to receive theposition information and to display position data reflective of theposition information, wherein the display device includes a processorand a memory device.

In an embodiment of the disclosed injection training system, a method oftracking the position of a testing tool used in an injection trainingsystem is described. The method includes obtaining position informationof the testing tool from one or more sensors; determining an estimate ofthe position of the testing tool; transmitting, to a display device,data reflective of the estimate of the position of the testing tool; anddisplaying, on the display device, the data reflective of the estimateof the position of the testing tool.

In an embodiment, an injection training system is disclosed. Theinjection training system includes a testing tool having a needle, aplunger, and a marker configured to reflect electromagnetic waves. Thesystem also includes an injection apparatus configured to receive asimulated injection by the testing tool. The injection apparatus alsohas a marker configured to reflect electromagnetic waves. The systemincludes an optical tracking system having a field of view, where theoptical tracking system is positioned such that the injection apparatusis in the field of view. The optical tracking system is configured toobtain position information of the testing tool and the injectionapparatus and to transmit the position information to a display device.The display device is configured to receive the position information andto display position data reflective of the position information.

In one embodiment, there are three main components of the trainingsystem: (1) a training apparatus (also referred to interchangeably as aninjection apparatus throughout the present disclosure) which features ananatomically accurate model of a human or human body part necessary forinjection training, (2) a light detection device, such as, for example,a camera, associated with the training apparatus, and (3) a testing toolwith light emitting capabilities. In an embodiment, a fourth componentof the training system can include an output device that can run anapplication which receives communications from the training apparatus orlight detection device and generates information regarding injectionparameters based on the communications from the injection apparatus orlight detection device. In an embodiment, the images captured by thecamera are processed by a processor included either in the injectionapparatus or in the light detection device before being communicated tothe output device. This processing can include, for example, determiningan indication of one or more injection parameters. In an embodiment, theanatomical model can include various injection conditions, such as, forexample, layered skin, available in multiple tones and textures to mimica diverse span of age, race, and skin texture. In an embodiment, thelayered skin can be removable and/or replaceable. The injectionapparatus can simulate any human or animal part, such as, for example,the face, head, brain, neck, back, chest, spine, torso, arms, legs,hands, feet, mouth, or any other body part or portion of the body ofinterest. In an embodiment, the testing tool can be, for example asyringe or hypodermic needle. In an embodiment, the injection apparatusis reusable. In an embodiment, the injection apparatus is disposable.

In an embodiment a syringe for simulating injection is disclosed. Thesyringe can include a barrel having a portal at a distal end, and anelectronics assembly having a light source at a distal end of theelectronics assembly. The electronics assembly can be configured to fitinside the barrel with the light source positioned at the portal of thebarrel. A needle can be attached to the barrel. The needle can have afiber bundle extending axially through it such that the fiber bundle isin close-fitting relation with the light source.

In some embodiments a testing tool for use in an injection trainingsystem includes a barrel having a fitting at a distal end of the barrel.The fitting can have a portal, and the barrel can have an opening and afinger grip at a proximal end of the barrel. A plunger can be configuredto fit in the opening of the barrel to apply a force directed axiallytoward the distal end of the barrel. The testing tool can include anelectronics assembly that has a light source at its distal end and aforce sensor at its proximal end. The electronics assembly can beconfigured to fit inside the barrel with the light source positioned atthe portal of the fitting, and the force sensor positioned near theproximal end of the barrel. The force sensor can be configured to sensethe force applied by the plunger. The testing tool can include a needleassembly attached to the fitting of the barrel. The needle assembly canhave a hollow needle, a fiber bundle extending axially through thehollow needle, and a hub configured to secure the hollow needle and toattach the needle assembly to the fitting of the barrel. The needleassembly can be attached to the barrel such that the fiber bundle withinthe hollow needle is in close-fitting relation with the light source ofthe electronics assembly.

In an embodiment, a method of simulating an injection into a syntheticanatomical structure is disclosed. The synthetic anatomical structurecan be configured to attenuate light emitted into it and to detect theattenuated light. The method can include providing a testing tool tosimulate a syringe. The testing tool can be configured to emit lightthrough a needle at a distal end of the testing tool. The method canalso include inserting the needle into the synthetic anatomicalstructure such that the light emitted through the needle is attenuatedand detected by the synthetic anatomical structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an injection training system comprising an injectionapparatus, a testing tool and an output device in accordance with anembodiment of the present disclosure.

FIG. 2A is a perspective view of an embodiment of an assembled testingtool.

FIG. 2B is an exploded perspective view of an embodiment of a testingtool.

FIG. 2C is a perspective view of an embodiment of a barrel of a testingtool.

FIG. 2D is a perspective view of an embodiment of a label of a testingtool.

FIG. 2E is a perspective view of an embodiment of a needle assembly of atesting tool.

FIG. 2F is an exploded perspective view of an embodiment of a needleassembly of a testing tool.

FIG. 2G is a top view of the distal end of an embodiment of the needleassembly of a testing tool.

FIG. 3A is a simplified block diagram of an embodiment of an electronicsassembly of a testing tool.

FIG. 3B is a perspective view of an embodiment of an electronicsassembly of a testing tool.

FIG. 3C is an exploded perspective view of an embodiment of a forcesensor sub-assembly of an electronics assembly of a testing tool.

FIG. 4A is a perspective view of an embodiment of a testing tool dockedin an embodiment of a docking station.

FIG. 4B is a perspective view of an embodiment of a docking station.

FIG. 4C is a perspective view of an embodiment of a docking station withits cover removed.

FIG. 5 illustrates an embodiment of the injection training system.

FIGS. 6A and 6B are two perspective views of an example trajectory foran injection.

FIG. 7 illustrates an example embodiment of a three-dimensional (3D)injection detection sensor.

FIG. 8 illustrates an example embodiment of a 3D injection detectionsensor.

FIG. 9 illustrates a side view of one embodiment of the injectionapparatus including a 3D injection detection sensor.

FIG. 10 is a process flow diagram of a method of manufacturing ananatomically shaped injection apparatus including a 3D tracking system.

FIG. 11 is a process flow diagram for a method of 3D injection training.

FIG. 12 illustrates an embodiment of an injection training systemcomprising an injection apparatus, a testing tool, and a resting cradlein which the testing tool follows a sequence of motion (A through D)from the resting cradle to an injection site of the injection apparatus.

FIG. 13A illustrates a process flow diagram of a process to determinethe position and orientation of a testing tool according to anembodiment of the disclosed injection training system.

FIGS. 13B, 13B1, and 13B2, collectively, illustrate a process flowdiagram of a process to determine the position and orientation of atesting tool according to an embodiment of the disclosed injectiontraining system.

FIG. 14A is simplified perspective view of an exemplary optical trackingsystem illuminating a testing tool according to an embodiment of thedisclosed injection training system.

FIG. 14B is simplified perspective view of an exemplary optical trackingsystem sensing reflected light from testing tool according to anembodiment of the disclosed injection training system.

FIG. 14C illustrates a testing tool configured with multiple markersaccording to an embodiment of the disclosed injection training system.

FIG. 14D illustrates aspects of the user interface/display deviceaccording to an embodiment of the disclosed injection training system.

FIG. 15A illustrates an embodiment of an injection training systemcomprising an injection apparatus, a testing tool, an output device andan optical tracking system, in accordance with an embodiment of thepresent disclosure.

FIG. 15B illustrates an embodiment of an injection training systemcomprising an injection apparatus, a testing tool, an output device anda plurality of optical tracking systems, in accordance with anembodiment of the present disclosure.

DETAILED DESCRIPTION

Embodiments will now be described with reference to the accompanyingfigures. The following description is merely illustrative in nature andis in no way intended to limit the disclosure, its application, or itsuses. For purposes of clarity, the same reference numbers will be usedin the drawings to identify similar elements. The terminology used inthe description presented herein is not intended to be interpreted inany limited or restrictive manner, simply because it is being used inconjunction with a detailed description of certain specific embodimentsof the disclosure. Furthermore, embodiments of the disclosure mayinclude several novel features, no single one of which is solelyresponsible for its desirable attributes or which is essential topracticing the present disclosure. It should be understood that stepswithin a method may be executed in different order without altering theprinciples of the present disclosure.

FIG. 1 depicts an embodiment of an injection training system 100. Aninjection apparatus 105, comprising a synthetic anatomical structure,can be used for any type of injection training involved withadministering diagnostic and therapeutic chemical substances. Forexample, injection training can be provided for epidural techniques andfor intra-cardiac injections. In one embodiment, the injection apparatus105 can anatomically model the face, neck, and head of a human oranimal. Although not shown in the accompanying drawings, the injectionapparatus 105 can model other injection sites including the chest, arms,mouth, back, buttocks, etc. The injection apparatus 105 may alsorepresent any body part of a human or animal, including internal organs.In some embodiments, the injection apparatus 105 may include a simulatedskull and layers of muscle and skin. The injection apparatus 105 can bepositioned on a base 108 to facilitate use on flat surfaces, such as atable or desk.

A testing tool 110 is also illustrated which can be used with theinjection apparatus 105 and in conjunction with a camera/light detector120 located within the injection apparatus 105. The testing tool 110 maysimulate any type of equipment used in connection with an injection orminimally invasive procedure, such as a needle, catheter or cannula. Asdescribed in further detail below, the camera/light detector 120 cancapture visual indications of the user's injection using the testingtool 110. The visual indications provide an operator or user withinformation regarding the location, depth, pressure, or angle of theinjection. In an embodiment, the testing tool 110 contains a lightsource that emits light through the needle portion of the testing tool110 which is used to aid in obtaining the visual indications detectableby a camera/light detector 120. The light source can emit visible light.In an embodiment, a gradient of white light is emitted through theneedle portion of the testing tool. Other colors of visible light canalso be used, such as green, blue, red, yellow or any combination ofthose colors. In an alternative embodiment, the light source may emitlight along a spectrum of visible or non-visible light, such asfluorescent, ultraviolet, or infrared light. In some embodiments, thelight emitted from the light source is attenuated differently dependingon which layer of simulated skin, muscle, or tissue the injectionapparatus 105 is penetrated. Different colors, directions, graph lines,visual patterns, polarization, fluorescence, or intensities of light canbe captured by the camera/light detector 120 as the testing tool 110 isinserted through the different layers of material surrounding theinjection apparatus 105. The resulting light detected by thecamera/light detector 120 can be used to determine the location of theinjection, the pressure exerted by the user, the angle of injection,and/or the depth of the injection. This information can be detected, forexample by a camera/light detector 120, and communicated to a userinterface/display device 140 for training, testing, and/or certificationpurposes. In some embodiments, information used to determine thelocation of the injection, the pressure exerted by the user, the angleof injection, and/or the depth of the injection can be collected by thetesting tool 110 and communicated to a user interface/display device 140and/or a camera/light detector 120 for training, testing andcertification purposes.

The camera/light detector 120 within the simulated skull of theinjection apparatus 105 captures the attenuated light emitted by thetesting tool 110, simulating an injection, through video recordingand/or photographic images. The camera/light detector 120 can include aprocessor and can communicate output from the camera/light detector 120to a user interface/display device 140. The information gathered fromthe camera/light detector 120 and testing tool 110 may be communicatedto a user interface/display device 140 for data collection, testing orcertification purposes. Output from the camera/light detector 120 can beraw or processed video or images obtained from the camera/light detector120. The processor of the camera/light detector 120 can include softwareconfigured to interpret the visual indications for testing purposes orcan merely pass images to the user interface/display device 140 forfurther processing. In an embodiment, the user interface/display device140 can also communicate instructions to the camera/light detector 120and/or to the testing tool 110.

Attention is now directed to embodiments of the testing tool 110.Although disclosed with reference to particular embodiments of thetesting tool 110, an artisan will recognize from the disclosure hereinthat there is a large number and wide variety of embodiments andconfigurations that may be used to perform the functions of a testingtool 110 as described herein.

FIGS. 2A and 2B illustrate (in assembled and exploded views,respectively) an embodiment of the testing tool 110 adapted for use totrain individuals to inject materials with a syringe. In an embodimentthe testing tool 110 includes a plunger 210, a barrel 220, a needleassembly 230, and an electronics assembly 240. Also illustrated arefasteners 221, such as screws, to secure portions of the electronicsassembly 240 to the barrel 220.

For purposes of this description, the end of the test tool 110 towardthe needle assembly 230 is referred to as the “distal end,” and motionor direction toward the distal end is described as being “distal.” Theend of the test tool 110 longitudinally opposite the distal end isreferred to as “the proximal end,” and motion or direction toward theproximal end is described as being “proximal.”

The plunger 210 can be manufactured by using many types of materialsincluding polypropylene, glass, and other materials known to skilledartisans. The plunger 210 includes a top portion 212 at the proximal endof the plunger 210. The plunger 210 also includes a shaft 214 which, inan embodiment, is x-shaped. In some embodiments the plunger shaft 214can be cylindrical or any other shape suitable to perform the functionof a plunger 210. In some embodiments, the plunger 210 is collapsible tosimulate the process of injecting material into a patient. In someembodiments the plunger 210 is configured to house the electronicsassembly 240. In some embodiments the plunger 210 is collapsible andconfigured to measure the plunger's 210 motion of contraction todetermine a volume of material that would have been injected under thesimulated circumstances and conditions of use of the testing tool 110.The collapsible plunger 210 can be reset by pulling it back to itsoriginal, un-collapsed (or extended) position. In some embodiments datareflecting the position of the plunger 210 is collected and communicatedto, for example, the user interface/display device 140 and/or to thecamera/light detector 120. In an embodiment the testing tool 110includes a hydraulic and/or a friction-based device, acting against theplunger 210, to simulate the force of resistance that a liquid materialwith certain properties of viscosity, would exert against the plunger210 as it is injected into a patient.

At the distal end of the plunger 210 is a seal 216, which is made ofrubber in an embodiment. A skilled artisan will appreciate that in someembodiments the plunger seal 216 may be made from any material suitablefor creating a seal between the plunger 210 and the inside walls of thebarrel 220, such as various types of elastomers and/or polymers. In someembodiments the plunger 210 lacks a seal 216 because the testing tool110 is not used to deliver liquid, chemical substances, thereby lackinga need to form a seal.

FIG. 2C is a perspective view of an embodiment of a barrel 220 of atesting tool 110. The barrel 220 can be made from many types ofmaterials including polypropylene, glass, and other materials known toskilled artisans. The barrel 220 includes a grip 222 and an opening 223at the barrel's proximal end. The grip 222 provides finger support forreciprocation of the plunger 210 relative to the barrel 220 during usefor training. At the distal end of the barrel 220 is a threaded portion224 configured to receive a fitting 226. The fitting has a portal 225through which light passes from a light source (on the electronicsassembly 240) to a fiber bundle housed within a hollow needle (in theneedle assembly 230). In some embodiments the fitting 226 can be a Luerfitting, a standardized set of fittings used to make leak-freemechanical connections between a male-taper fitting and a mating femalepart on medical and laboratory instruments, including hypodermic syringetips and needles. In some embodiments the fitting 226 is not tapered.Advantageously, in some embodiments, the fitting 226 can accommodatenumerous configurations of needle assemblies 230 corresponding tovarious injection indications and applications. In some embodiments acustomized fitting 226 includes a thread with no taper component tofacilitate intimate contact between a light source and a fiber bundlethat transmits the emitted light into the injection apparatus 105. In anembodiment the barrel 220 includes bores 228 configured to receiveconnector pins attached to the electronics assembly 240 to enablecharging of a battery when, for example, the testing tool 110 is housedin a docking station. The barrel 220 also includes holes 229 throughwhich fasteners, such as screws, can be used to secure the electronicsassembly 240 to the barrel 220.

FIG. 2D is a perspective view of an embodiment of a label 250 of atesting tool 110. In an embodiment, the label 250 is configured to fitinside the barrel 220 in close-fitting relation with an inner wall ofthe barrel 220. In an embodiment the label 250 is configured to fitoutside the barrel 220 in close-fitting relation with an outer wall ofthe barrel 220. The label 250 can be configured to present any type ofinformation including, among other things, branding and/or instructionalinformation.

FIGS. 2E-2F are perspective views (assembled and exploded, respectively)of an embodiment of a needle assembly 230 of a testing tool 110,including a hollow needle 232, a needle hub 234, an adapter 236, and afiber bundle 238 positioned centrally along the longitudinal axis of theneedle assembly 230 and configured to transmit light at the distal endof the testing tool 110. In some embodiments a needle hub 234 isconfigured to connect directly to the fitting 226 of the barrel 220,thereby eliminating the need for an adapter 236. The fiber bundle 238 ishoused within the hollow needle 232. In an embodiment the hollow needle232 is made from hypodermic tubing. A wide variety of hollow needles 232used for, among other things, hypodermic applications, have outerdiameters described by gauge numbers ranging from 7 to 34. Hollowneedles 232 within this gauge range can be used in various embodimentsof the disclosed needle assembly 230. Smaller gauge numbers indicatelarger outer diameters. The inner diameters of such hollow needles 232depend on both gauge and wall thickness. Thin-wall needles haveidentical outer diameters, but larger inner diameters, for a givengauge. Thin-wall needles can also be used in various embodiments of theneedle assembly 230. In an embodiment the hollow needle 232 is made ofstainless steel and has a gauge size of 23RW. A skilled artisan willappreciate that the hollow needle 232 can be of many different gaugesizes without departing from the scope of the disclosure herein. Freespace between the fiber bundle 238 and the inner wall of the hollowneedle 232 can be potted with optical epoxy. The proximal and distalends of the hollow needle 232, having the fiber bundle 238 securedinside it, can be polished flat. The hollow needle 232 can beepoxy-bonded to the needle hub 234, which attaches to the fitting 226 onthe barrel 220. FIG. 2G is a top view of the distal end of the needleassembly 230 illustrating the fiber bundle 238 housed and secured withoptical epoxy within the hollow needle 232.

FIG. 3A is a simplified block diagram of an embodiment of theelectronics assembly 240 of the testing tool 110. Functionally, amongother things, the electronics assembly 240 emits light from a lightsource 320, measures the electronic assembly's 240 physical positionand/or orientation with a position sensor 308, and measures forceapplied to the plunger 210 by a force sensor 312. The electronicsassembly 240 communicates the measured position information and themeasured force information to, for example, an external userinterface/display device 140, and/or to a camera/light detector 120, byway of a communications protocol. In some embodiments the electronicsassembly 240 communicates data by way of a USB port 322 using a cablethat has a minimal diameter and is highly compliant. In some embodimentsthe electronics assembly 240 communicates data by way of a radio 310employing, for example, a Bluetooth wireless communications protocol.

As illustrated in FIG. 3A, an embodiment of the electronics assembly 240includes a battery 302, a power management controller 304, a voltageregulator 306, a position sensor 308, a radio 310, a force sensor 312, adata acquisition system 314, one or more processors 316, a light sourcedriver 318, a light source 320 and one or more power/communication ports322. In some embodiments the battery 302 is rechargeable, and the powermanagement controller 304 is configured to communicate with an externalbattery-charging power/communication port 322, such as, for example, auniversal serial bus (USB) port. The battery 302 can supply power to thecomponents and circuitry of the electronics assembly 240. In anembodiment the battery 302 is an ultrathin, rechargeable, lithiumpolymer cell. A skilled artisan will appreciate that numerous otherbatteries can be used in the disclosed electronics assembly 240.

According to an embodiment, the electronics assembly 240 comprises abattery 302 and a light source 320, where the electronics assembly 240is configured to emit light through the hollow needle 232 to achievebasic functionality of the disclosed testing tool 110. In an embodiment,the electronics assembly 240 comprises a light source 320 and a port 322through which an external power source may be electrically connected toenergize the light source 320 to achieve basic functionality of thetesting tool 110. One skilled in the art will appreciate that variousfunctional capabilities described in connection with embodiments of theelectronics assembly 240 can be implemented in numerous ways. Toillustrate this point, illustrative components, blocks, modules, andcircuits have been described generally in terms of their functionality.The manner by which such functionality is implemented can depend uponthe particular application and design constraints imposed on the overallsystem. The described functionality can be implemented in varying waysfor each particular application, but such embodiment decisions shouldnot be interpreted as causing a departure from the scope of the presentdisclosure.

To operate effectively in the injection training system 100, the lightsource 320 must be sensed by the camera/light detector 120. In anembodiment the camera/light detector 120 is configured to sense visiblelight and infrared light. In an embodiment the light source is a lightemitting diode (LED) that emits low, infrared light at a wavelength of810 nanometers (nm). In an embodiment the light source 320 is a laserthat emits low infrared light at a wavelength of 850 nm. In anembodiment the light source 320 has a narrow emission angle of twentydegrees or less. In an embodiment, the light source 320 is an LED thathas its dome removed and is polished flat to facilitate intimate contactwith the proximal end of the fiber bundle 238 and the light source 320when the testing tool 110 is assembled. In some embodiments lenses,reflectors, and/or fiber optic tapers are coupled to the light source320 to focus and/or to intensify the emitted light in the direction ofthe fiber bundle 238. In some embodiments the intensity of the lightemitted by the testing tool 110 is proportional to the amount ofpressure applied to a plunger 210 of the testing tool 110, therebysimulating a process by which liquid material is injected through thetesting tool 110. A skilled artisan will appreciate that many otherlight sources 320 and light ranges of various wavelengths can be used inthe disclosed training system 100 without departing from the scope ofthe disclosure herein.

In an embodiment the force sensor 312 is configured to sense up totwenty pounds (20 lbs.) of force with a 2 percent accuracy factor. In anembodiment the position sensor 308 is a three-axis digital gyroscopewith angle resolution of two degrees and with a sensor drift adjustmentcapability (pitch, yaw and roll) of one degree. A skilled artisan willappreciate that numerous other position sensors 308 and force sensors312 can be used in the disclosed electronics assembly 240 withoutdeparting from the scope of the disclosure herein. In an embodiment theelectronics assembly includes a power conditioning component, such as avoltage regulator 306, to enable operation of the position sensor 308and the force sensor 312. In an embodiment the position sensor 308senses the position of the testing tool 110 in three-dimensional space,and the sensed position information is communicated to the userinterface/display device 140 and/or to the camera/light detector 120.

FIG. 3B is a perspective view of an embodiment of the electronicsassembly 240. Advantageously, the electronics assembly 240 is configuredto fit within the barrel 220 of the testing tool 110. A rectangularcircuit board 324 comprises a substrate onto which several components ofthe assembly 240 are attached. In an embodiment the electronics assemblyincludes the battery 302, the power management controller 304, thevoltage regulator 306, the light source driver 318 and the light source320. When the electronics assembly 240 is configured in the testing tool110, it is positioned such that the light source 320 is located at thedistal end of the testing tool 110, within the fitting 226 so as to makeintimate contact with the proximal end of the fiber bundle 238, which issecured to the needle assembly 230.

In an embodiment the electronics assembly 240 also includes a forcesensor sub-assembly 360 illustrated in FIG. 3B and in FIG. 3C, inassembled and exploded views, respectively. The force sensorsub-assembly 360 has a circular printed circuit board 326 comprising asubstrate to which several components of the force sensor sub-assembly360 are attached, including a force sensor 312, backstops 328, andconnector pins 330. The backstops 328 provide structural support for theforce sensor sub-assembly 360 and serve as a mechanism by which tosecure the force sensor sub-assembly 360 to the barrel 220. The circularprinted circuit board 326 is attached to the two backstops 328 withfasteners 329. The connector pins 330 are used to couple to an externalpower source to charge the battery 302. In an embodiment, the connectorpins 330 are spring-loaded contacts that are soldered to the circularprinted circuit board 326 and configured to fit through the bores 228 inthe barrel 220. By protruding through the bores 228 the connector pins330 are able to make electrical connection with an external power sourceto enable charging of the battery 302.

When positioned within the testing tool 110, the force sensorsub-assembly 360 is oriented substantially perpendicular to therectangular printed circuit board 324 such that the force sensor 312 isconfigured to sense axial force applied in the distal direction by theplunger 210. The force sensor sub-assembly 360 is secured to the barrel220 by fasteners 221 (shown in FIG. 2B), such as flat head screws, thatare inserted through the holes 229 of the barrel 220 and secured intothreaded screw holes 362 located centrally on the backstops 328. In thismanner the force sensor sub-assembly 360 resists being deflected inresponse to force applied to the force sensor 312 by the plunger 210.

In an embodiment the circular printed circuit board 326 is electricallycoupled to the proximal end of the rectangular printed circuit board 324to enable electrical communication between the force sensor 312 and theprocessor 316, and between the connector pins 330 and the powermanagement controller 304.

An artisan will recognize from the disclosure herein that thefunctionality of the electronics assembly 240 may be accomplished inmany different ways, using many different electronic components andorganized in a large number of ways without departing from the scope ofthe disclosure herein.

Referring back to FIGS. 2A-2B, assembly of the testing tool 110, forsome embodiments, is accomplished by securing the needle assembly 230 tothe fitting 226, and by securing the electronics assembly 240 into thebarrel 220. Spring-loaded connector pins 330 retract inward to permitthe electronics assembly 240 to move to the distal end of the inside ofthe barrel 220, such that the light source 320 is in close intimaterelation with the proximal end of the fiber bundle 238 of the needleassembly 230. The electronics assembly 240 may be rotated axially suchthat the spring-loaded connector pins 330 are aligned with bore holes228, at which point the spring-loaded connector pins will expand to lockinto position. Fasteners 221 are then used to secure the electronicsassembly 240 to the barrel 220. The plunger 210 is inserted into theproximal end of the barrel 220.

In some embodiments the plunger 210 is configured to move distallythrough the barrel 220 when force is applied to the plunger 210, therebysimulating the plunger motion associated with injecting material into apatient. In an embodiment, the plunger shaft 214 is cylindrical, havingan outer diameter slightly less than the inner diameter of the barrel220. As the cylindrical plunger shaft 214 moves through the barrel 220in the distal direction, the plunger shaft 214 slides around andenvelops the electronics assembly 240. In an embodiment, a resistancedevice offers a resistive force in response to the force applied to theplunger 210, corresponding to a resistive force experienced wheninjecting liquid materials into a patient. In an embodiment theresistive device is a friction-based device. In an embodiment theresistive device is a fluid-based device. In an embodiment the resistivedevice includes a spring configured to apply a resistive force to theplunger 210. One skilled in the art will readily appreciate that thereare many ways by which to achieve the functionality of the resistivedevice. In an embodiment, the force applied by the plunger 210 and theforce applied by the resistive device are sensed and communicated to auser interface/display device 140 and/or to a camera/light detector 120.

In some embodiments the plunger shaft 214 is configured to collapsetelescopically to simulate plunger motion associated with injectingmaterial into a patient. In some embodiments, the collapsible plungershaft 214 is configured to sense positional displacement of the plungershaft 214 and to communicate the plunger shaft 214 displacementcoordinates to a user interface/display device 140 and/or to acamera/light detector 120. In some embodiments measurements of theposition of a movable, collapsible or telescoping plunger 210 arecommunicated to a user interface/display device 140 and/or to acamera/light detector 120 and used to determine whether proper doses arebeing delivered.

In some embodiments, the electronics assembly 240 is positioned withinthe plunger shaft 214, and is configured to move distally and proximallythrough the barrel 220, along with the plunger 210. Placing theelectronics assembly 240 in a hollowed shaft 214 of the plunger 210makes the barrel 220 available to hold a therapeutic agent that can beinjected during the training into the injection apparatus 105. Theposition sensor 308 is configured to obtain position and orientationinformation of the testing tool 110 and of the plunger 210, and towirelessly transmit the information to the user interface/display device140. In an embodiment, the force sensor sub-assembly 360 can bepositioned within the shaft 214 of the plunger 210 to measure theresistive force of the therapeutic agent in the barrel 220, as theinjection is applied. The measured force information can be wirelesslytransmitted to the user interface/display device 140. Illustratively, insuch an embodiment the testing tool 110 operates in a manner similar toa syringe in that the testing tool 110 is configured to deliver atherapeutic agent through the needle 232 into the injection apparatus105. In some embodiments the electronics assembly 240 is positionedwithin the plunger shaft 214 and is configured to move distally andproximally through the barrel 220, along with the plunger 210. The lightsource 320 is positioned at the distal end of the barrel 220, and aflexible connector connects the light source 320 to the electronicsassembly 240. In some embodiments the flexible connector connecting thelight source 320 to the electronics assembly is extendable andretractable. Accordingly, the plunger 210 is able to move axially intoand out of the barrel 220, while the light source is configured to emitlight through the tip 233 of the hollow needle 232.

FIG. 4A illustrates an embodiment of a testing tool 110 docked in adocking station 400. The docking station 400 includes a dock cover 402,a USB port 404, and two indicator lights 406. The docking station 400 iscontoured to accommodate the testing tool 110 such that the connectorpins 330 of the testing tool 110 are in contact with contact pins 408 tofacilitate charging of the battery 302. FIG. 4B provides a view of acontact pin 408 of the docking station 400. FIG. 4C illustrates thedocking station 400 with its cover 402 removed revealing a dock circuitboard 410 electrically coupled to the USB port 404 and to the indicatorlights 406. The dock circuit board 410 is also electrically coupled tocontact pins 408 such that when a connection is made from, for example,a standard power outlet to the USB port 404, the contact pins areconfigured to support charging of the battery 302 of the testing tool110 when the testing tool is docked in the docking station 400. Standoffelements 412 are employed to provide appropriate spacing within thestructure of the docking station 400.

In some embodiments of the injection training system 100, an injectiontraining apparatus 105 or method can use one or more three-dimensional(3D) position sensors to determine a position of a testing tool 110,such as a syringe and/or needle, in an artificial patient injection site(such as, for example, an artificial face). One or more 3D positionsensors can also be used for training caregivers on performinginjections where accurate positioning is important, such as in facialinjections (e.g., Botox®), spinal injections, and/or the additionalinjections described above.

By integrating one or more 3D sensors, the injection training apparatusand method may provide enhanced accuracy when tracking the trainee'sinjection technique. Increased training accuracy can facilitateincreased detail on the feedback provided to the trainee. The featuresdiscussed below with reference to FIGS. 5-11 may be included, in wholeor part, with the training systems, methods, and devices describedherein.

FIG. 5 illustrates an embodiment of the injection apparatus 105, testingtool 110 and user interface/display device 140. The injection apparatus105 shown forms a head bust with realistic look and feel of human flesh.The external surface of the injection apparatus 105 may be asubstantially synthetic or simulated skin. The synthetic or simulatedskin can be an opaque rubber or other material which simulates skin andfacial features of real patients. Underlying the skin may be a layer ofsubstantially clear rubber (and/or any suitable elastomer) whichsimulates the viscosity, elasticity, and feel of skin, muscle, nerve,and bone tissue of a patient. The opaque skin and clear underlay may becapable of being pierced by a needle. It should be noted that theinjection apparatus 105 need not include colored underlying skin toattenuate light.

The injection apparatus 105 is hollow and includes, within the cavity, athree-dimensional (3D) sensor 502. The 3D sensor 502 may include acamera, an array of light detectors or other sensor(s) capable ofdetecting a location of an object in three dimensions. The 3D sensor 502is configured to detect a position of a needle and/or to view theinterior surface of the injection apparatus 105. A field of view 504 isestablished in front of the 3D sensor 502. The field of view 504represents an area in which the 3D sensor 502 may detect light.

A testing tool 110 is also shown. The testing tool 110 may beimplemented as a syringe equipped with a light emitting needle, forexample, as described in greater detail above. The light emitted by thetesting tool 110 may be detected by the 3D sensor 502.

As shown in FIG. 5, the 3D sensor 502 and the testing tool 110 arecoupled with a signal processing and display interface 555 via cables560 and 570. The signal processing and display interface 555 can includeone or more processors configured to receive and process information,provided from the 3D sensor 502 and/or from the testing tool 110 thatcorresponds to the position of the testing tool 110 relative to theinjection apparatus 105. Illustratively, the processing and displayinterface 555 processes the received information from the 3D sensor 502and from the testing tool 110 to determine the testing tool's 110position relative to the injection apparatus 105. Although illustratedin FIG. 5 as being coupled by wires, coupling between the 3D sensor 502,the testing tool 110, and the user interface/display 140 can beaccomplished via wired, wireless, or a combination of wired and wirelessconfigurations. Moreover, the processing and interface 555 can beincorporated into the user interface/display 140. The method of couplingthe 3D sensor 502 need not be identical to the method of coupling usedfor the testing tool 110.

In use, as illustrated in FIG. 5, a trainee punctures the face of theinjection apparatus 105 with the testing tool 110 which is emittinglight from a tip 233 of the hollow needle 232. When the tip 233 passesthrough the opaque skin layer of the injection apparatus 105, the 3Dsensor 502 is configured to detect the light emitted from the tip 233and to determine the three-dimensional position, in space, of the tip233. The three-dimensional position information is transmitted to thesignal processing and display interface 555, which is configured tocommunicate the three-dimensional position information to the userinterface/display device 140. The user interface/display device 140integrates the communicated position information into a digital model ofthe head bust injection apparatus 105. The user interface/display device140 may be configured to present a visual representation of the positionof the needle tip 233 relative to the injection site on the injectionapparatus 105. The user interface/display device 140 allows the traineeto evaluate the actual needle position, as represented on the userinterface/display device 140, in comparison to the ideal position, whichis also represented on the user interface/display device 140. The userinterface/display device 140, shown in FIG. 5, is coupled with thesignal processing and display interface 555 by a cable 580. The couplingmay be via wired, wireless, or a combination of wired and wirelessconfigurations.

The three-dimensional position information relative to the 3D sensor 502is mapped in software to a graphical representation of the injectionsite on the user interface/display device 140. This mapping is performedby determining accurate three-dimensional coordinates corresponding tothe position of the injection apparatus 105 in the world. The positionof the 3D sensor 502 relative to the injection apparatus 105 is alsodetermined with a high degree of precision. This precision allows a veryaccurate mapping of the detected three-dimensional position informationof the hollow needle 232 and its tip 233 to be accurately detected bythe 3D sensor 502 and accurately mapped in software to recreate theposition of the needle 232 and the needle tip 233 of the testing tool110. This information is then used to determine both the accuracy of theinjection relative to a predetermined injection site accuracy goal, aswell as to provide a graphical illustration of the injection, againrelative to the injection site goal. This mapping and display can beprovided substantially in real time so that a user can adjust thetrajectory of injection during the training.

FIGS. 6A and 6B illustrate two views of a trajectory for an injection.FIG. 6A illustrates a view from the perspective of the 3D sensor 502,positioned inside the injection apparatus 105 and directed at the innersurface of the injection apparatus 105. To orient the reader, an eye 602and a nose 604 have been labeled. An injection starting point 610 isdetected by the 3D sensor 502. As the needle tip 233 proceeds into theinjection apparatus 105, the changing positions of the light emittedfrom the needle tip 233 are measured by the 3D sensor 502. In someimplementations, the measurement may be a video capture of theinjection. In some implementations, the measurement may be a sampledcapture at, for example, predetermined intervals. A trajectory path 630,from the starting point 610 to an ending point 620, is thus obtained. Asshown in FIG. 6A, the trajectory path 630 takes the form of an irregularinjection path, which may, in some circumstances, indicate the need foradditional training.

The trajectory path 630 may be presented via the user interface/displaydevice 140. The presentation may include providing a line tracking theinjection path. The presentation may include providing an animateddepiction of the injection. In some implementations, the presentationmay be augmented with additional information such as identifying andshowing which muscles, skin, body parts, etc. the injection is coming incontact with or is penetrating. The augmentation of the presentation mayretrieve one or more models of the desired physiological informationfrom a data store. The models include three-dimensional informationindicating the location(s) of certain anatomical or physiologicalfeatures. The feature information, along with the three-dimensionalinjection location information, is mapped onto the presentation of theinjection apparatus 105.

Because three-dimensions of information are being obtained, multipleviews of the injection trajectory may be provided. FIG. 6B provides asecond view of the injection trajectory shown in FIG. 6A. FIG. 6Billustrates a view taken from an overhead perspective of a horizontalcross-section of the injection apparatus 105. The cross-section is takenat a point on the injection apparatus 105 which allows the viewer to seea horizontal injection trajectory path 660 of the needle. As in FIG. 6A,to orient the reader, the eye 602 and the nose 604 have been labeled.

The horizontal injection trajectory path 660 begins at the startingpoint 610 and ends at the ending point 620. However, because theperspective has changed, the shape of the path 660 is different thanthat shown in FIG. 6A. This provides another view of the injectionresult. It will be understood that the presentation model may bearbitrarily rotated, and a representation of the trajectory path for therepresentational model, as rotated, may be generated. The rotation maybe provided to the system as a display point of view identifying thelocation in space from which to view the trajectory path. Because theinjection apparatus digital model is combined with the three-dimensionalinjection information and, in some instances, anatomical orphysiological information, the injection training may provide a widevariety of views, depending on the technique needed for the injection.The views may be provided as animated depictions, such as video orreconstructed animations. For example, in some embodiments, historicaltrajectories for the same type of injection can be shown in a 3D overlapview which illustrates historical injection trajectories to a currentinjection trajectory. In this way, a care provider can visually comparetrajectory information for improvement progression analysis and generalaccuracy analysis. Different historical trajectories can be shown indifferent colors, shades, and/or highlights in order to illustrate ageand/or accuracy of the trajectories.

The aspects shown in FIG. 5 allow a trainee to adjust his or hertechnique and monitor his or her progress toward the ideal injectiontechnique. For example, the user interface/display device 140 mayprovide a view selector (not shown) to allow the trainee to see theinjection site from a variety of views, such as rotated, zoomed in,zoomed out, cross-sectional, time-lapsed, and the like, both in realtime and after the injection has occurred. As shown in FIG. 5, across-sectional view is displayed on the user interface/display device140 whereby the trainee can see how far through an opaque skin layer 590into a clear material layer 592 the testing tool has passed.

In some implementations, the three-dimensional position informationreceived from the 3D sensor 502 may be converted before integration intothe digital model of the injection apparatus 105. In suchimplementations, the received three-dimensional position information maybe calibrated, adjusted, or otherwise converted such that the positioninformation of the testing tool 110 may be correlated with a position onthe digital model of the injection apparatus 105.

As discussed, one or more sensors may be provided within the trainingapparatus 105 which provide three-dimensional position information forthe testing tool 110. FIG. 7 illustrates an example embodiment of a 3Dsensor 502. A dimensional legend 799 is provided to indicate the threeaxes (e.g., X, Y and Z) of detection. This dimensional legend 799 islogical and may not physically be included in an embodiment of theinjection training systems described. The names attributed to each axismay differ, but each axis should represent one unique dimension.

The 3D sensor 502 is shown receiving light from a testing tool 110 at afirst position 702, and then at a second position 704. These positionsare not simultaneous, but rather represent the sequential movement ofthe testing tool 110 over time. The light emitted from the testing tool110 is received by the 3D sensor 502. The light is emitted from the tip233 of the testing tool 110 and disperses on its way to the 3D sensor502. As shown in FIG. 7, a first area of light 710 is generated when thetesting tool is located at the first position 702. A second area oflight 712 is generated at a second time when the testing tool 110 islocated at the second position 704. The 3D sensor 502 may be configuredto measure one or more characteristics of the received light andgenerate information corresponding to the three-dimensional position ofthe testing tool 110 based on the characteristics detected.Illustratively, the characteristics may include angle, intensity,brightness, color, dispersion, and/or duration of the light.

In one implementation, the 3D sensor 502 may include an array of lightsensors. As light is emitted from the needle tip 233, one or more of thesensors in the array may receive light. By aggregating the informationabout which sensors received light and characteristics of the lightreceived at each sensor, three-dimensional information about theposition of the light source may be determined. Some 3D sensors 502 maybe housed in a recess and, based on the light pattern cast on thesensor, determine the location of the light source. In generating the 3Dlocation information, the 3D sensor 502 may also obtain calibrationinformation for the needle tip 233 of the testing tool 110 to accountfor variability, such as in manufacturing, wear-and-tear, and power.Further calibration information may be used to specify the field of view504 for the 3D sensor 502. The calibration information may be received,for example, through an initialization sequence whereby the testing tool110 is placed at a predetermined location on the injection apparatus.

Because the 3D sensor 502 knows the light source and its particularlocation vis-à-vis the light source, the 3D sensor 502 can generateaccurate and, in some implementations, real-time 3D location informationfor the testing tool 110.

FIG. 8 illustrates another embodiment of a 3D sensor 502. It may bedesirable to implement the 3D sensor 502 as a stereoscopic sensor pair.A dimensional legend 899 is provided indicate the three axes (e.g., X, Yand Z) of detection. This dimensional legend 899 is logical and may notphysically be included in an embodiment of the injection trainingsystems described. The names attributed to each axis may differ, buteach axis should represent one unique dimension.

The 3D sensor pair includes a first 3D sensor 502A and a second 3Dsensor 502B. The first 3D sensor 502A and the second 3D sensor 502B areconfigured to receive, at substantially the same time, light from atesting tool 110. The testing tool 110 may be located at differentpositions at different times. FIG. 8 shows a first position 810 at afirst time, and a second position 812 at a second time, for the testingtool 110.

Each 3D sensor 502A and 502B is configured to measure one or morecharacteristics of the light transmitted from the testing tool's 110position and to generate three-dimensional location informationcorresponding to the position of the testing tool 110, based in thedetected characteristics. The characteristics may include angle,intensity, dispersion, brightness, color, or duration of the sensedlight. Combining the characteristic data received from the first 3Dsensor 502A and the second 3D sensor 502B, three-dimensional informationfor the testing tool 110 may be generated. The combination may beperformed by one of the 3D sensors 502A and 502B, or by the signalprocessing and display interface 555. In an embodiment the combinationcan be performed in the user interface/display device 140.

In generating the 3D location information, the generation of thethree-dimensional information may also include obtaining calibrationinformation for the needle tip 233 to account for variability such as inmanufacturing, wear-and-tear, and power. The calibration information maybe received, for example, through an initialization sequence whereby thetesting tool 110 is placed at a predetermined location on the injectionapparatus 105.

FIG. 9 depicts a side view of one embodiment of the injection apparatus105, including a 3D sensor 502. The injection apparatus 105 is formed asa human head. A testing tool 110 is shown inserted into the injectionapparatus 105. The testing tool 110 may be implemented as describedabove, such as in reference to FIGS. 2A-G, 3A-C and 4A-C. To minimizediffraction of the light emitted from the testing tool 110, a surface ofclear elastomer 910 may be made substantially perpendicular to thedirection of light travel. Accordingly, in an embodiment the innersurface of the clear elastomer 910 is formed as a spherical surface withthe center facing a 3D sensor 502. The 3D sensor 502 may be implementedas described above such as in reference to FIGS. 5, 7 and 8. The 3Dsensor 502 is configured to detect light emitted by the testing tool 110within a field of view 504.

Rather than utilize a light emitting testing tool 110 in combinationwith a single two-dimensional (2D) camera that detects a two-dimensionalposition of the light emitting needle tip 233, the injection trainingsystem 100 may include one or more 3D sensors 502 and/or trackingequipment. With a single 2D camera, a position with respect to a thirddimension may be determined, for example, by tinting the clear elastomersurface 910, causing a color of the light to change as the needle tip233 transitions through the tinted layer. Illustratively, the color maytrend toward white light as the needle tip 233 moves closer to the innersurface of the clear elastomer surface 910.

It may be desirable to avoid tinting the clear elastomer surface 910 andallow the use of 3D tracking equipment, such as 3D sensors 502 (whichmay be cameras or other types of sensors), examples of which are shownin FIGS. 7 and 8 above. Further examples of 3D tracking equipmentinclude equipment sold by Personal Space Technologies B.V. (available athttp://ps-tech.com/). An additional example of 3D tracking equipment isdescribed in a Centre Suisse d'Electronique et Microtechnique SA (CSEM)Scientific & Technical Report entitled “spaceCoder: a Nanometric 3DPosition Sensing Device,” which is incorporated by reference herein inits entirety.

As the testing tool 110 penetrates an opaque skin layer 590 and entersthe internal clear elastomer layer 592, the 3D sensor 502 detectscharacteristics of the light which can be used to generate athree-dimensional location of the testing tool 110. For example, it maybe desirable to track a desired range 912 of needle penetration. In someimplementations, the depth information is displayed on a display, suchas the user interface/display device 140, as the testing tool 110 isinserted. This allows a trainee to visualize the location of theinjection in near real-time. The signal processing and display interface555 may provide the location information to facilitate such displays. Insome implementations, the feedback may be provided in audio form such asa beep or an alert.

FIG. 10 shows a process flow diagram of a method of manufacturing ananatomically shaped injection apparatus 105 including a 3D sensor 502,such as that shown in FIG. 9. The method includes, at block 1002,forming an at least partially hollow base configured to providestructural support for a target injection test area. The methodincludes, at block 1004, coating at least a portion of the base with aclear layer of elastomer. The method also includes, at block 1006,coating at least a portion of the clear layer with an opaque layer. Thebase, clear layer, and opaque layer form an anatomical shape such as askull. The method further includes, at block 1008, affixing athree-dimensional (3D) tracking system (which can include one or more 3Dsensors 502) within the hollowed portion of the base, wherein thethree-dimensional tracking system provides a field of view of the clearlayer covering the target injection test area. The three-dimensionaltracking system may be a 3D camera such as that shown in FIG. 7 or astereoscopic camera pair such as those shown in FIG. 8. In someimplementations, the method may also include coupling the 3D trackingsystem with a location processor configured to provide locationinformation for a light source inserted into the clear layer. Thelocation information identifies a three-dimensional location of thelight source relative to the injection apparatus 105. The locationprocessor may be implemented in the signal processing and displayinterface 555 shown in FIG. 5.

FIG. 11 illustrates a process flow diagram for a method ofthree-dimensional (3D) injection training. The method may be performedin whole or in part by one or more of the devices described herein suchas the training apparatuses described above.

The method includes, at block 1102, calibrating at least one of a lightsource and a three-dimensional tracking system. The light source may bea light emitter located at the tip 233 of a testing tool 110. Thethree-dimensional tracking system may include a 3D camera, astereoscopic camera pair, or other sensor configured to providethree-dimensional location information for the light source. The methodalso includes, at block 1104, detecting, by the three-dimensionaltracking system, a characteristic of light emitted from the light sourcefor an injection. The characteristic may include intensity, angle,dispersion, brightness, color, or duration of the light. In someimplementations, an array of sensors may be used to detect light. Insuch implementations, the characteristic may include which sensors inthe array of sensors received light. The method further includes, atblock 1106, generating three-dimensional location information of thelight source based on the detected characteristics and said calibrating.

In some embodiments, the testing tool 110 is configured to determine itsposition and orientation in three-dimensional space relative to theinjection apparatus 105. The testing tool 110 is also configured tocommunicate its position and orientation information to other componentsof the injection training system 100, such as, for example, the userinterface/display device 140. The user interface/display device 140 candisplay, in near real time, the testing tool's 110 position relative tothe injection apparatus 105, as injection training is performed. Thetesting tool 110 can also communicate its position and orientationinformation to the 3D sensor 502 and/or to the signal processing anddisplay interface 555.

In an embodiment, the position sensor 308 collects nine dimensions ofsensed information to determine the 3D position and orientation of thetesting tool 110 in space with adequate accuracy. This is becauseprocessing sensed three-dimensional angular velocity provided by a 3Dgyroscope leads to an accumulating error in the calculated position andorientation of the testing tool 110. To compensate for this erroraccumulation, measurements from a 3D accelerometer and from a 3Dmagnetometer can be used. The 3D accelerometer measures the earth'sgravitational field, and the 3D magnetometer measures the earth'smagnetic field. Together, the sensed information from the 3Daccelerometer and 3D magnetometer can provide an absolute reference oforientation that can be used to compensate for the progressivelyaccumulating error of the sensed and processed angular velocity dataprovided by the 3D gyroscope. A method for sensor fusion includesprocessing the measured nine dimensions of sensed information (from the3D gyroscope, the 3D accelerometer, and the 3D magnetometer) todetermine a single estimate of position and orientation of the testingtool 110, in three-dimensional world coordinates.

In an embodiment, the position sensor 308 of the testing tool 110comprises a inertial measurement unit (IMU) that includes one or moreaccelerometers, one or more gyroscopes, one or more magnetometers toprovide, in near real time, information describing the 3D position andorientation of the testing tool 110. In some embodiments, the positionsensor 308 can also include an embedded processor that handles, amongother things, signal sampling, buffering, sensor calibration, and sensorfusion processing of the sensed inertial data. The position sensor 308can also include a wireless network protocol for data transmission toexternal components, such as, for example, the user interface/displaydevice 140, the 3D sensor 502, and the signal processing and displayinterface 555. Illustratively, the position sensor 308 senses, processesand transmits sensed position and orientation data of the testing tool110 to a sensor fusion processing component that can be configured tooperate on, for example, the user interface/display device 140. In anembodiment, the position sensor 308 transmits already-processed positionand orientation information, delivered in three-dimensional, worldcoordinates, to the user interface/display device 140 which graphicallydisplays the position of the testing tool 110 relative to the injectionapparatus 105 in near real time as the injecting training occurs. Theposition sensor 308 can provide calibrated 3D linear acceleration, 3Dangular velocity, 3D magnetic field, and optionally, atmosphericpressure data, to the sensor fusion processing component which processesthe data to deliver precise position and orientation information of thetesting tool 110. In an embodiment, the sensor fusion processingcomponent employs a Kalman filter to provide three degrees-of-freedomposition and orientation information of the testing tool 110 relative tothe injection apparatus 105. The sensor fusion processing component usesdata collected from the gyroscopes, accelerometers and magnetometers tocompute a statistical, optimal 3D position and orientation estimate, ofhigh accuracy and with no drift, for movements of the testing tool 110.

Illustratively, the sensor fusion processing component comprises analgorithm in which the measurement of gravity (by the 3D accelerometers)and the earth's magnetic north (by the 3D magnetometers) compensate forotherwise slowly, but steadily increasing drift errors from theprocessing (using mathematical integration) of rate-of-turn data(angular velocity) measured from the rate gyroscopes. The describedapproach for compensating for drift can be referred to as attitude andheading referenced, and a system that employs this approach can bereferred to as an Attitude and Heading Reference System (AHRS).

FIG. 12 illustrates an embodiment of an injection training system 100comprising an injection apparatus 105, a testing tool 110, and a restingcradle 1202 in which the testing tool 110 follows a sequence of motion(A through D) from the resting cradle 1202 to an injection site of theinjection apparatus 105. In FIG. 12, the injector's hand is not shown tobetter illustrate the motion of the testing tool 110. At position A, thetesting tool 110 sits in the resting cradle 1202. The resting cradle1202 is in a known, fixed position relative to the injection apparatus105. This can serve to calibrate the injection training system 100 toknow where the testing tool 110 is located relative to the injectionapparatus 105 at the initiation of the injection training. In anembodiment, the resting cradle 1202 is attached to the base 108 of theinjection apparatus 105. In an embodiment, the injection apparatus 105has calibration points 1204 that can be used to establish an initialposition of the testing tool 110 relative to the injection apparatus105.

Starting from the known position relative to the injection apparatus105, such as from the resting cradle 1202, the movement of the testingtool 110 can be determined, even as the needle tip 233 penetrates thematerial of the artificial face. By way of non-limiting illustration,the testing tool is lifted from the resting cradle 1202 to position B.The testing tool 110 is rotated to position C, where the needle tip 233is directed toward the injection apparatus 105. At position D, theneedle tip 233 of the testing tool 110 is inserted into the injectionapparatus 105. Position information corresponding to the testing tool110, including the needle tip 233, can be conveyed to a digital model ofthe injection apparatus 105. The digital model includes target tissue(individual muscles) and details of vital structures (VS, which is alsoreferred to as vital tissue, VT), such as, for example, arteries, veins,nerves, and skeletal portions, that are to be avoided or accommodated.By comparing the position of the needle tip 233, based on the determinedposition of the testing tool 110, to the target tissues and the vitalstructures illustrated on the user interface/display device 140,proximity to a desired injection target can be established. Thisproximity to target and to vital structures can serve as the basis forevaluating the skill of the injection trainee.

Various manufacturers offer for sale inertial measurement systems,devices, and methods, including sensor fusion processing components, forincorporation into products and systems. Such manufacturers includeXsens Technologies, B.V., of Enschede, the Netherlands; InvenSense, Inc.of Sunnyvale, California, USA; and Synopsys, Inc., of Mountain View,California, USA. Examples of systems, devices and/or methods forinertial measurement of objects in three-dimensional space are disclosedin U.S. Pat. No. 7,725,279B2, issued on May 25, 2010; U.S. Pat. No.8,165,844B2, issued on Apr. 24, 2012; U.S. Pat. No. 8,203,487B2; issuedon Jun. 19, 2012; U.S. Pat. No. 8,250,921B2, issued on Aug. 28, 2012;U.S. Pat. No. 8,351,773B2, issued on Jan. 8, 2013; and in U.S. PatentApplication Publication Numbers 2009/0278791A1, published on Nov. 12,2009; and 2009/0265671A1, published on Oct. 22, 2009, each of which isincorporated by reference herein in its entirety.

Computation of the position and orientation of an object inthree-dimensional space is a task that can process inputs from severalsensors to achieve accurate estimates of the position and orientation ofthe object. The method can be referred to generally as a fusion ofsensor inputs. A sensor fusion process can reduce the impact of, and/orcompensate for, inaccuracies of senor measurements and/or processingapproximations. Disclosed herein is a system and method to implement afusion process that is computationally efficient and that includes ninedimensions of sensor input. In an embodiment, the system includes aprocessor that can be supplemented with hardware accelerators to helpreduce power consumption. An example of a system, device and method tocompute the 3D orientation of an object by processing nine dimensions ofdata using a sensor fusion process is described in a paper entitled“Ultra Low-Power 9D Fusion Implementation: A Case Study,” by PieterStruik, which is incorporated by reference herein in its entirety.

The disclosed system and method to fuse sensor information is one amongmany possible sensor fusion approaches. One skilled in the art willappreciate that there are numerous systems and methods for fusing sensorinput to derive accurate position and orientation information of anobject in three-dimensional space without departing from the spirit ofthe present disclosure. The disclosed system and method offers effectivetracking performance while executing computations that are similar tothose used by other sensor fusion processes. Performance optimizationfor this embodiment is based on an analysis of processing-intensiveactivities. One approach to optimization is to employ a fixed pointprocessing implementation. Another approach to optimization can includethe use of one or more hardware accelerators to execute certaincomputations efficiently. Such optimization approaches are directed atreducing the number of processing cycles required to determine accurateestimates of the position and orientation of an object inthree-dimensional space.

Described herein is a system and method to calculate three-dimensional(3D) position and orientation of an object derived from inputs fromthree motion sensors attached to the object: an accelerometer configuredto measure linear acceleration along three axes; a gyroscope configuredto measure angular velocity around three axes; and a magnetometerconfigured to measure the strength of a magnetic field (such as theearth's magnetic field) along three axes. In an embodiment, the threemotion sensors are attached to the testing tool 110. In an embodimentthe three motion sensors are integrated into a single position sensor308, as reflected in FIG. 3A. In an embodiment, the sensors are sampledat a rate of 50 Hz; however, one skilled in the art will appreciate thatthe sensors can be sampled at different rates without deviating from thescope of the present disclosure. The sampled data from the three motionsensors, which provide nine sensor inputs, are processed to describe thetesting tool's 110 position and orientation in three-dimensional space.The testing tool's position and orientation are described in terms ofEuler angles as a set of rotations around a set of X-Y-Z axes of thetesting tool 110.

Theoretically, the method to determine orientation angles around thethree axes of the testing tool 110 is a straightforward process thatincludes mathematically integrating the three angular velocitymeasurements provided by the 3D gyroscope sensor. However, whenimplemented, sensor drift and/or processing approximations can lead to asteadily increasing set of errors that affect the accuracy of suchdeterminations. A method to compensate for the inaccuracy of theprocessed angular velocity measurements includes processingaccelerometer data and magnetometer (or compass) data, in a sensorfusion process. The disclosed system and method to fuse sensor inputapplies principles that are comparable in accuracy to systems andmethods that employ techniques of linear quadratic estimation, such asKalman filtering, which may also be used to fuse sensor input data insome embodiments.

The disclosed system and method to fuse sensor input uses quaternionalgebra to determine a present position and orientation of the testingtool 110. In practical application, quaternions can be used inconjunction with other processing methods, such as Euler angles androtation matrices, to calculate rotations of objects inthree-dimensional space. Illustratively, a quaternion, where Q=[q0 q1 q2q3], can define a three-by-three rotation matrix “R” that translateseach coordinate x=(x,y,z) of the initial testing tool's 110 orientationinto its current position, Rx. A product (known as the Hamilton productin quaternion algebra, which is represented by the symbol “⊗”) of twoquaternions, such as Q0⊗Q1, delivers another quaternion that describes acompound rotation performed by a first rotation, described by Q0, whichis followed by a second rotation, described by Q1. Use of quaternionalgebra can reduce computational processing requirements because most ofthe computations used to perform quaternion algebra do not employcomputationally-intensive trigonometric functions.

FIG. 13A illustrates a process flow diagram of a process 1300 todetermine the position and orientation of a testing tool 110 accordingto an embodiment of the disclosed injection training system 100. Oneskilled in the art will appreciate that there are numerous ways by whichthe position and orientation of the testing tool 110 can be determinedwithout departing from the scope of the present disclosure. At block1302, the process begins by collecting measured data from the 3Dgyroscope, the 3D accelerometer, and the 3D magnetometer. The samplingrate can vary, depending on the components used to implement theprocess.

At block 1304, the present orientation of the testing tool 110 isrepresented by a quaternion “Q” which represents the currently measuredangular acceleration data from the 3D gyroscope. This quaternion is aninitial estimate of the position and orientation of the testing tool110. The present orientation can be updated with information provided bythe gyroscope sensor which may be represented as (gx, gy, gz).Additional rotation of the testing tool 110 that occurred since the mostrecent measurement can be represented by a quaternion [1 (gx/f) (gy/f)(gz/f)], where f is defined as a sampling frequency used to execute thesensor fusion process. This representation may be expressed asquaternion [C gx gy gz ], with “C” being a constant that is proportionalto the sampling frequency, f.

At block 1306, information provided by an accelerometer sensor is usedto help compensate for accuracy errors in the angular velocity dataprovided by the gyroscope sensor. An acceleration vector (ax, ay, az),measured by the accelerometer, will equal the acceleration of gravitywhen the testing tool 110 is not in motion. When the testing tool 110 isin motion, its rotation can be characterized by rotation R, and thevector corresponding to gravity is directed towards the earth's center.When viewed relative to the motion of the sensors attached to thetesting tool 110, the gravity vector will have been rotated by the samerotation R. Accordingly, the initial gravity vector v becomes Rv,relative to the testing tool 110, after rotation has taken place. If thetesting tool 110 is not moving, the computed gravity vector, Rv, will bealigned with the measured accelerometer information (ax, ay, az). WhenRv and (ax, ay, az) are pointing in different directions, we determinethat rotation R is inaccurate and, therefore, the coordinatesrepresenting the present orientation, Q, must be adjusted based on thevector cross product Rv×(ax, ay, az).

At block 1308, fusion with information sensed by the magnetometer canalso be applied. It is assumed that the testing tool 110 is subject tothe earth's magnetic field. It is also assumed that the testing tool 110is not subject to interference from a separate magnetic field, such as,for example, the field of a permanent magnet. Under these assumedconditions, the magnetic field measured by the 3D magnetometer (mx, my,mz) can be related to the initial orientation of the testing tool 110 byapplying a reverse rotation R*, where the vector w=R*(mx, my, mz). It isalso assumed that the earth's magnetic north is aligned in the directionof the X axis. Accordingly, an alignment error can be determined bycomparing the vector w to a vector w′, which is obtained by rotating thevector w onto the plane of the testing tool 110. An alignment errorvector c can be calculated. The alignment error vector, c, isproportional to the vector cross product c=w×w′. As c is related to theinitial orientation of the testing tool 110, Rc corresponds to theadjustment that can be applied to the testing tool's 110 presentposition and orientation, represented by quaternion Q.

At block 1310, the adjusted quaternion Q is converted into three Eulerangles. Euler angles are a way of representing the spatial orientationof a coordinate system as a composition of three elemental rotations,starting from a known, standard orientation. The relation between thequaternion Q and the converted Euler angles includes calculations thatuse inverse sine and inverse tangent functions. Illustratively, therotation angle around the Y axis is determined with the followingconversion equation: Y=−asin(2*q1*q3+2*q0*q2), where the quaternionQ=[q0 q1 q2 q3].

In an embodiment, the method 1300 to determine the position andorientation of a testing tool 110 updates the position and orientationof the testing tool 110 at the sampling rate of the sensors.Accordingly, at block 1312, the process 1300 determines whether thepresent injection training is continuing or whether it has ended. Whenthe present injection training is continuing, the method 1300 returns toblock 1302 to update the position and orientation information of thetesting tool 110. When the present injection training is completed, theprocess 1300 terminates at block 1314.

FIGS. 13B, 13B1, and 13B2, collectively, illustrates a process flowdiagram of a process 1340 to determine the position and orientation of atesting tool 110 according to an embodiment of the disclosed injectiontraining system 100. Illustratively, process 1340 discloses one approachto implementing process 1300, described above. One skilled in the artwill appreciate that there are numerous ways by which process 1300 canbe implemented without departing from the scope of the presentdisclosure.

At block 1350, the process begins by collecting measured data from the3D gyroscope (providing angular momentum information), the 3Daccelerometer (providing linear accelerations information), and the 3Dmagnetometer (providing magnetic field information). The presentposition and orientation of the testing tool 110 is represented by aquaternion, based on the measured angular acceleration data from the 3Dgyroscope. Blocks 1352 through 1358 illustrate computation actionsimplemented to compensate for inaccuracies in the angular velocity data,provided by the 3D gyroscope, based on the linear accelerationinformation provided by the 3D accelerometer. This methodology uses theearth's gravitational field to identify inaccuracies in the measuredangular momentum data and to compensate for those inaccuracies. At block1352, the measured 3D accelerometer data is compared with a rotatedinitial gravity vector. At block 1354, the accelerator data is invertedand normalized. At block 1356, a vector cross product of the normalizedaccelerator data and the rotated gravity vector is computed. And atblock 1358, a compensation for gyroscope data inaccuracies is made,using a constant acceleration compensation factor.

Blocks 1360 through 1368 illustrate actions implemented to compensatefor inaccuracies in the angular velocity data, provided by the 3Dgyroscope, based on the magnetic field information provided by the 3Dmagnetometer. This methodology uses the earth's magnetic field toidentify inaccuracies in the measured angular momentum data and tocompensate for those inaccuracies. At block 1360, the measured 3Dmagnetometer data is normalized and inverted. At block 1362, an inverserotation of the normalized magnetometer data is computed. At block 1364,the computed rotation is aligned in orientation with the testing tool110, based on earth's magnetic north. At block 1366, the computedrotation is rotated back to the original orientation, and an alignmenterror vector is computed by computing a cross product of rotation vectorwith the measured magnetometer data. At block 1370, a compensation forgyroscope data inaccuracies is made, using a constant magneticcompensation factor. At block 1370, the testing tool's position andorientation, represented in a quaternion, is updated based on theadjusted gyroscope data, and it is normalize at block 1372. At block1374, the updated position and orientation information of the testingtool 110 is converted into Euler angles which can be used by, forexample, the user interface/display device 140 to graphically displaythe position of the testing tool 110. At block 1376, the process 1340returns to block 1350, to begin another iteration when the injectiontraining is continuing. Alternatively, the process terminates at block1378 when the injection training is finished.

Advantageously, the disclosed method for determining the position andorientation of a testing tool 110 is robust, even when assumptions arenot held. For example, when the testing tool 110 is moving, the measuredaccelerometer data (ax, ay, az) represents a non-zero linearacceleration relative to gravity; however the sensor fusion processingmethod nevertheless delivers accurate position data. Moreover, fusion ofmagnetometer data proves to be accurate in the presence of distortion inthe gravitational magnetic field.

In an embodiment, the disclosed method can be implemented in a system ofintegrated hardware and software (or firmware) that can be optimized toprocess data from digital and analog sensors and to engage inpower-efficient processing of the sensor data. The system can include aprocessor (such as the ARC EM4 32-bit processor core offered by SynopsysInc.), a user-configurable set of serial digital interfaces,analog-to-digital converter interfaces, hardware accelerators, and asoftware library of digital signal processor (DSP) functions andinput/output (I/O) software drivers. The system can take advantage ofcapabilities to implement tightly coupled I/O peripherals and tightlycoupled hardware accelerators, which may be accessed directly from theprocessor pipeline without the overhead of additional hardwareinfrastructure, such as, for example, busses, bridges, and/or adapters.

In an embodiment, the system configuration contains one or moreInter-Integrated Circuit (I2C) master peripheral ports, a SerialPeripheral Interface (SPI) master peripheral port, and a general purposeinput/output (GPIO) port. The processor can be configured to have asingle-cycle 32-bit integer multiplier. The system can be configured toinclude one or more fixed-point hardware accelerators to performcomputationally-intensive operations, such as, for example,multiply-accumulate (MAC) operations, trigonometric operations, and thesquare root operation. Illustratively, use of hardware accelerators canreduce processor cycle time with respect to computationally-intensiveoperations such as the square root operation. A hardware acceleratoraccepts a 32-bit fixed point number as input and computes the squareroot in 31 cycles, evaluating one bit at a time which is substantiallyfaster than calculating a square root by use of software delivered aspart of a compiler's standard library.

Many of the required computations used in the disclosed method arecomputationally-intensive when implemented using standard softwareroutines. For example, rotation and inverse rotation operations arematrix-vector multiplications where the (inverse) rotation matrix hascoefficients that are based on the quaternion Q. Illustratively, inverserotation operations involve many multiplications and additions.Similarly computing the inverse norm of a vector or a quaternionrequires the following operations: multiplication, addition, squareroot, and division. Likewise, computing a vector cross product requiresmultiplication operations and addition operations. Computing theHamilton product of two quaternions takes many multiplications andadditions. Computing Euler angles involves trigonometric functions (atan2 and asin), where the arguments are expressions that are based onquaternion Q. These expressions include multiplication operations andaddition operations. Use of one or more hardware accelerators toimplement such operations can reduce overall processing time and powerconsumption.

To further improve performance and to reduce power consumption thedisclosed system, device and method can be configured to be implementedusing fixed point arithmetic as opposed to using floating pointarithmetic. Conversion of numerical processing using floating pointarithmetic to fixed point arithmetic requires care with respect tooverflow and underflow in computations. However, after such conversionis performed successfully, the processing workload can be reduced byreplacing floating point multiplication operations with single-cycle,32-bit multiplications, and floating point addition operations withsimple, 32-bit additions (or subtractions). Evaluation of the resultingfixed-point version of the disclosed method shows that the square rootfunction, which is executed four times in each cycle of the disclosedmethod, consumes many processing cycles. Using a standard square rootfunction call, which is typically included in a library of digitalsignal processing (DSP) functions, to apply the square root hardwareaccelerator can further reduce processing cycle count. Anotheroptimization can be to reduce the cycle count of the Euler anglescomputation by applying a hardware accelerator for the inverse sinefunction. Because the inverse tangent function can be expressed in termsof the inverse sine and square root operations, using the hardwareaccelerators for thee computations reduces computational workload, powerconsumption, and processing time per iteration. Thus the processingcycle count of the disclosed nine-dimensional sensor fusion method canbe reduced by implementing a fixed point version of the process thattakes advantage of available hardware accelerators. Reduction of cyclecount leads to lower energy, as the energy that is used for executingthe algorithm is proportional to the required performance.

In an embodiment, position sensors 308 are used in both the barrel 220of the testing tool 110 and in the plunger 210 of the testing tool 110to determine the position of the plunger 210 relative to the barrel 220of the testing tool 110. This information can be used to indicate distaltravel movement of the plunger 210 in the testing tool 110 duringsimulated injection. The distal travel movement can represent a volumeof fluid that would be injected, and therefore the distal travelmovement can be used to determine a measure of the injection trainee'sperformance.

An embodiment of the disclosed system, device and method to determinethe position and orientation of the testing tool 110, relative to theinjection apparatus 105, during injection training includes the use ofone or more retro-reflectors attached to the testing tool 110 inassociation with an optical tracking system. A retro-reflector(sometimes called a retroflector or cataphote) is a device or surfacethat reflects light back to its source with a minimum of scattering. Ina retro-reflector, an electromagnetic wave front is reflected back alonga vector that is parallel to, but opposite in direction from, the wave'ssource. The angle of incidence at which the device or surface reflectslight in this way is greater than zero, unlike a planar mirror, whichreflects an electromagnetic wave (such as light) only if the mirror isexactly perpendicular to the wave front, having a zero angle ofincidence. The retro-reflectors are locatable by an optical trackingsystem that can operate in, for example, the infrared (IR) range. Theretro-reflectors can be positioned on the external surface of thetesting tool 110 for use with optical tracking systems that operate byuse of infrared illumination. This type of optical tracking allows forthe triangulation of energy reflected from the retro-reflectors todetermine the testing tool's 110 position in three-dimensional space. Inan embodiment, alignment of the needle tip 233 with the injectionapparatus 105 can be accomplished by touching the needle tip 233 to aknown location on the injection apparatus 105, such as calibrationpoints 1204.

FIGS. 14A and 14B are perspective views of an exemplary optical trackingsystem 1400. Optical tracking is a 3D localization technology thatmonitors a defined measurement space using two or more light sensors1402, such as, by way of non-limiting example, cameras. In anembodiment, each light sensor 1402 is equipped with an infrared (IR)pass filter (not shown) in front of the lens, and a ring of IR lightemitting diodes (not shown) around the lens to periodically illuminatethe measurement space of the optical tracking system 1400 with IR light,as illustrated in FIG. 14A. Reflections from markers 1404 on the testingtool 110 are sensed by the light sensors 1402, and the sensedinformation is processed by the optical tracking system 1400 todetermine the position and orientation of the testing tool 110 inthree-dimensional space. Examples of optical tracking systems 1400 aredescribed in a paper entitled “PST iris: Instruction Manual,” publishedby Personal Space Technologies B.V, and in International PatentApplication Number PCT/NL2009/050607, having International PublicationNumber WO 2011/043645A1, published on Apr. 14, 2011, which areincorporated by reference herein in their entirety.

Computer stereo vision is the extraction of 3D information from digitalimages, such as obtained by a charge-coupled device camera. By comparinginformation about a scene from two vantage points, 3D information can beextracted by examination of the relative positions of objects in the twopanels. In traditional stereo vision, two cameras, displacedhorizontally from one another are used to obtain two differing views ona scene, in a manner similar to human binocular vision. By comparingthese two images, the relative depth information can be obtained, in theform of disparities, which are inversely proportional to the differencesin distance to the objects. To compare the images, the two views aresuperimposed in a stereoscopic device. In camera systems, severalpre-processing steps are required. The image is removed of distortions,such as barrel distortion to ensure that the observed image is a pureprojection. The image is projected back to a common plane to allowcomparison of the image pairs, known as image rectification. Aninformation measure which compares the two images is minimized. Thisgives the best estimate of the position of features in the two images,and creates a disparity map. Optionally, the disparity as observed bythe common projection, is converted back to a height map by inversion.Using a correct proportionality constant, the height map can becalibrated to provide precise distances. Active stereo vision is a formof stereo vision which actively employs a light, such as an infraredlight source, to simplify the stereo matching problem. An examples of astereo vision system and processing method is disclosed in U.S. Pat. No.8,208,716B2, issued on Jun. 26, 2012, which is incorporated by referenceherein in its entirety.

Objects to be tracked, such as the testing tool 110, can be equippedwith retro-reflective markers 1404 that reflect the incoming IR lightback to the light sensors 1402. The IR reflections are detected by thelight sensors 1402 and then internally processed by the optical trackingsystem 1400. The optical tracking system 1400 calculates the 2D markerposition, in image coordinates, with high precision. Using at least twolight sensors 1402, the 3D position of each marker 1404 can be derived,as described above. The 3D position can be measured by using a singlemarker 1404 in the measurement space; however, to be able to alsomeasure the orientation of an object (or to track multiple objectssimultaneously), multiple markers 1404 must be placed on each object.Such a configuration can be created by affixing markers 1404 randomlyonto the object, making sure at least two markers 1404 can be seen fromeach angle of the object that the user desires to be detected. Byestablishing a model of the configuration of each object, the opticaltracking system 1400 can distinguish between objects and can determinethe 3D position and orientation of each object.

Optical tracking systems 1400 offer some advantages over otherapproaches to measure and determine the 3D position and orientation ofan object in three-dimensional space. For example, optical tracking isless susceptible to noise from the environment, such as, for instance,ferromagnetic metal in the environment which can influence the accuracyof the measurements of magnetic tracking systems. Additionally, opticaltracking does not suffer from drift problems experienced in, forinstance, inertial sensors, which cause measurements to slowly deviatefrom actual values, for which compensation techniques must be applied.Optical tracking also allows for many objects to be trackedsimultaneously. Optically tracked devices can be lightweight and they donot require wires or power. As such, users are neither hampered by wiresnor limited in their manipulation of the object.

FIG. 14C illustrates a testing tool 110 configured with multiple markers1404, in accordance with an embodiment of the present disclosure. In anembodiment, an optical tracking system 1400 measures the 3D positions ofmarkers 1404, such as, for example, retro-reflectors, affixed to thetesting tool 110. The markers 1404 can be active or passive. Using thisinformation, the optical tracking system 1400 can determine the positionand orientation of the marked testing tool 110 within a specific fieldof view defined by the optical tracking system. The optical trackingsystem 1400 can be a self-contained, integrated system that does notrequire external processing or calibration components. The opticaltracking system 1400 can be connected to the user interface/displaydevice 140 via a wired or by a wireless communication scheme. Theoptical tracking system 1400 can deliver 3D position and orientationmeasurement of the testing tool 110 to the interface unit/display device140. Advantageously, the disclosed optical tracking system 1400 deliversfully-processed position and orientation data to the userinterface/display device 140, thereby freeing up the processingcapability of the user interface/display device 140 for othercomputationally-intensive activities, such as, for example, processingand rendering of a digital model representative of the injectionapparatus 105 and the testing tool 110 during injection training.

FIG. 14D illustrates, among other things, aspects of the userinterface/display device 140 according to an embodiment of the disclosedinjection training system 100. Shown in magnified perspective areexamples of how the user interface/display device 140 can graphicallydisplay, either during the injection training or afterwards, thelocation of the needle tip 233 as it penetrates the injection apparatus105. The user interface/display device 140 illustrates portions of theanatomy in the vicinity of the injection site. In particular, vitaltissue (VT), and muscle are represented digitally on the userinterface/display device 140. Advantageously, the user can view a targetsite, a proximity to the target site, and nearby vital tissues orstructures. In some embodiments, visual and/or aural signals aredelivered to the trainee as indications of the needle tip's 233proximity to the target site. During an injection, for example, thedisplay can graphically illustrate the different skin and tissue layersas the needle tip 233 penetrates each layer. For example, this can bedone by graphically peeling back the layers as a new layer ispenetrated. For training purposes, the different layers can be labeledor provided with different textures or colors to indicate a new layer isshown.

In an embodiment, a single optical tacking system 1400 can track thetesting tool 110 in an injection training environment, as illustrated inFIG. 15A. In an embodiment, multiple optical tracking systems 1400 canbe coupled together to extend the workspace environment or to reduceissues due to the line-of-sight requirement of the optical trackingsystem 1400, as illustrated in FIG. 15B. In an embodiment, the opticaltracking system 1400 can be configured with different opticsconfigurations to adapt the field of view and the performancecharacteristics of the optical tracking system 1400 to the intendedenvironment and application. Illustratively, optics with a higher fieldof view result in a wider tracking area closer to the system, whereasoptics with a lower field of view provide a narrower, but longer,tracking area.

The optical tracking system 1400 can use tangible, wireless devices for3D interaction and 3D measurement, such as the testing tool 110. In anembodiment, the position and orientation (sometimes referred to as the“pose”) of the testing tool 110 can be reconstructed with millimeteraccuracy. Advantageously, the optical tracking system 1400 can be basedon infrared lighting, which can reduce the interference of visible lightsources from the environment. This allows the optical tracking system1400 to be used under normal, ambient working conditions withoutrequiring controlled lighting. The testing tool 110, and the injectionapparatus 105, can be tracked by applying retro-reflective markers 1404to their external surfaces. The optical tracking system 1400 employsthese markers to recognize different objects and to reconstruct theirposes. In an embodiment, and by way of non-limiting illustration, theoptical tracking system 1400 reconstructs the pose of the testing tool110, and optionally, of the injection apparatus 105, at an adjustablesampling frequency with a maximum of 120 times per second. One skilledin the art will appreciate that other sampling frequencies can be usedwithout departing from the scope of the present disclosure. The opticaltracking system 1400 can be triggered externally, such that it can besynchronized to external clock sources. This can, for instance, be usedto prevent interference between the internal infrared flash and shutterglasses that are synchronized to a 3D monitor, such as the userinterface/display device 140, using an infrared signal.

In an embodiment, tracking devices comprise physical objects, such asthe testing tool 110 and the injection apparatus 105, that can berecognized by the optical tracking system 1400 and of which the 3Dposition and orientation can be measured. In an embodiment, such devicescan be used to measure the spatial coordinates of objects, or forinstance, to interact with virtual 3D objects in an application.Illustratively, just as a mouse can be used to position a pointer intwo-dimensional space, so too can a tracking device be used to positionan object in three-dimensional space, with six degrees of freedom. The3D position and orientation (pose) of a tracking device, such as thetesting tool 110, is optically tracked, ensuring wireless operation.Retro-reflective markers 1404 can be applied to objects, such as thetesting tool 110 and the injection apparatus 105, to transform them intotracking devices. The tracking system uses these markers 1404 torecognize devices and to reconstruct each pose. In order for the opticaltracking system 1400 to be able to determine the position andorientation of a tracking device, at least four markers 1404 need to beapplied. The size of the markers 1404 helps to determine the optimaltracking distance. The optical tracking system 1400 supports flatretro-reflective markers 1404 for the construction of tracking devices.Such flat retro-reflective markers 1402 do not hamper manipulation.

In an embodiment, the markers 1404 are locatable by tracking systems,devices, and methods that can operate in the radio frequency (RF) range.The markers 1404 can be positioned on the interior of the testing tool110 for tracking systems 1400 that operate through use of RFillumination, such as the technology known as radio-frequencyidentification (RFID). Advantageously, the RF energy is able to betransmitted through the tissue of the injector's hand, arm and otherportions of the injector's body that may obstruct the requiredline-of-site view between an optical tracking system 1400 and thetesting tool 110 during injection training, when implemented usingoptical tracking systems 1400 based on infrared illumination.

In an embodiment, the reflective markers 1404 comprise cornerreflectors. Corner reflectors can operate in a wide range ofelectromagnetic frequencies including the infrared and the radiospectrums. A corner reflector is a retro-reflector comprising threemutually perpendicular, intersecting flat surfaces. The corner reflectorreflects waves back directly towards the source, but shifted(translated). The three intersecting surfaces often have square shapes.Optical corner reflectors, called corner cubes, made of three-sidedglass prisms, are used in surveying and laser range-finding. Theincoming ray is reflected three times, once by each surface, whichresults in a reversal of direction. The three corresponding normalvectors of the corner's perpendicular sides can be considered to form abasis (a rectangular coordinate system) (x, y, z) in which to representthe direction of an arbitrary incoming ray, [a, b, c]. When the rayreflects from the first side, say x, the ray's x component, a, isreversed to −a while the y and z components are unchanged, resulting ina direction of [−a, b, c]. Similarly, when reflected from side y andfinally from side z, the b and c components are reversed. So the raydirection goes from [a, b, c] to [—a, b, c] to [—a, —b, c] to [—a, —b,—c] and it leaves the corner reflector with all three components ofdirection exactly reversed. The distance traveled, relative to a planenormal to the direction of the rays, is also equal for any ray enteringthe reflector, regardless of the location where it first reflects.

In an embodiment, the optical tracking system 1400 views the testingtool 110 and the needle tip 233 as it approaches and penetrates theinjection apparatus 105. The optical tracking system 1400 can operate inthe visual and infrared spectrums. For optical tracking systems 1400using the infrared spectrum, an improvement in resolution anddifferentiation is available by altering the temperature of the testingtool 110 and/or the needle tip 233 to be different (hotter or colder)than ambient temperature. Infrared thermography (IRT), thermal imaging,and thermal video are examples of infrared imaging science.Thermographic cameras detect radiation in the infrared range of theelectromagnetic spectrum (roughly 9,000-14,000 nanometers or 9-14 μm)and produce images of that radiation, called thermograms. Since infraredradiation is emitted by all objects above absolute zero according to theblack body radiation law, thermography makes it possible to see one'senvironment with or without visible illumination. The amount ofradiation emitted by an object increases with temperature; therefore,thermography allows one to see variations in temperature. When viewedthrough a thermal imaging camera, warm objects stand out well againstcooler backgrounds.

The testing tool 110 and needle tip 233 can be clearly resolved againstthe ambient temperature background when using thermal imaging. In anembodiment, the 3D sensor(s) 502 from the interior of the injectionapparatus 105 can be configured to sense both light emitting from thetesting tool 110 and thermal energy emitted from the testing tool 110and/or needle tip 233 by use of infrared, or other forms of thermalimaging. Multiple methods for achieving temperature variation of thetesting tool 110 relative to ambient temperature can be used, including,without limitation, resistive heating on the testing tool 110 interiorwith conductive heat transfer to the hollow needle 232, and routing gasof a controlled temperature through a tube into the testing tool 110interior and exhausting the gas through the needle tip 233. In anembodiment, thermal imaging is available by including temperaturemarkers on the injection apparatus 105 to be viewable by a the opticaltracking system 1400, which can support accurate resolution of thetesting tool's 110 position relative to the injection apparatus 105. Inan embodiment, the depth of penetration of the needle tip 233 into theinjection apparatus 105 can be determined by measuring the length of theneedle 232 remaining exterior to the injection apparatus 105, therebyexposed to the view of the optical tracking system 1400. By knowing theorientation and position of the testing tool 110 relative to theinjection apparatus 105, along with the measured length of the needle232 remaining exterior to the injection apparatus 105, the depth ofpenetration of the needle tip 233 in the injection apparatus 105 may bedetermined.

In an embodiment, position information provided by the 3D sensor(s) 502and the optical tracking system 1400 can be combined to determine theposition and orientation of the testing tool 110 and the needle tip 233relative to the injection apparatus 105 during injection training.Combination of position data corresponding to the light emitting needletip 233 as the needle tip 233 passes through the opaque layer ofartificial skin, as sensed by the 3D sensor(s) 502 from the interior ofthe injection apparatus 105, with the length of the needle 232 remainingexterior to the injection apparatus 105, as sensed by the opticaltracking system 1400, can be combined to determine the position andorientation of the testing tool 110 and the needle tip 233 relative tothe injection apparatus 105.

An injection training system has been disclosed in detail in connectionwith various embodiments. These embodiments are disclosed by way ofexamples only and are not to limit the scope of the claims that follow.One of ordinary skill in the art will appreciate from the disclosureherein any variations and modifications.

Terminology/Additional Embodiments

The term “injection” as used herein includes it usual and customarymeaning of an injection, but is also to be interpreted broad enough toencompass, for example, the insertion of a catheter device or the use ofsimple needles, such as would be used in an acupuncture therapy. Thetechniques involved, particularly a camera embedded in a model of aliving subject and a tool with a light emitter can be applied to anytherapeutic procedure. For example, the tool can be a catheter and theprocedure can be a minimally invasive procedure requiring the catheterto be located in a particular location.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orstates. Thus, such conditional language is not generally intended toimply that features, elements and/or states are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without author input or prompting,whether these features, elements and/or states are included or are to beperformed in any particular embodiment.

Depending on the embodiment, certain acts, events, or functions of anyof the methods described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not alldescribed acts or events are necessary for the practice of the method).Moreover, in certain embodiments, acts or events can be performedconcurrently, e.g., through multi-threaded processing, interruptprocessing, or multiple processors or processor cores, rather thansequentially.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein can be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. The described functionalitycan be implemented in varying ways for each particular application, butsuch embodiment decisions should not be interpreted as causing adeparture from the scope of the disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein can be implementedor performed with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor can be a microprocessor, but in thealternative, the processor can be any conventional processor,controller, microcontroller, or state machine. A processor can also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The blocks of the methods and algorithms described in connection withthe embodiments disclosed herein can be embodied directly in hardware,in a software module executed by a processor, or in a combination of thetwo. A software module can reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, a hard disk, a removabledisk, a CD-ROM, or any other form of computer-readable storage mediumknown in the art. An exemplary storage medium is coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium can beintegral to the processor. The processor and the storage medium canreside in an ASIC. The ASIC can reside in a user terminal. In thealternative, the processor and the storage medium can reside as discretecomponents in a user terminal.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the devices or algorithms illustrated can be madewithout departing from the spirit of the disclosure. As will berecognized, certain embodiments of the disclosures described herein canbe embodied within a form that does not provide all of the features andbenefits set forth herein, as some features can be used or practicedseparately from others. The scope of certain disclosures disclosedherein is indicated by the appended claims rather than by the foregoingdescription. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

1.-160. (canceled)
 161. An injection training system, the systemcomprising: a signal processing and display interface comprising one ormore processors; and a display device in communication with the signalprocessing and display interface, the display device configured tovisually display a three-dimensional likeness of an anatomical structureas a stereoscopic representation, wherein the display device isconfigured to display one or more layers of the anatomical structurebeing peeled back.
 162. The injection training system of claim 161,wherein the anatomical structure is an injection site.
 163. Theinjection training system of claim 161, wherein the three-dimensionallikeness of the anatomical structure comprises a face.
 164. Theinjection training system of claim 161, wherein the signal processingand display interface is configured to retrieve one or more models ofphysiological information from a database.
 165. The injection trainingsystem of claim 164, wherein the one or more models includethree-dimensional information indicating location(s) of certainanatomical or physiological features of the anatomical structure. 166.The injection training system of claim 161, wherein thethree-dimensional likeness of the anatomical structure on the displaydevice is configured to be displayed with a plurality of differentviews.
 167. The injection training system of claim 166, wherein theplurality of different views comprise rotated, zoomed in, zoomed out,cross-sectional, or time-lapsed views.
 168. The injection trainingsystem of claim 161, wherein the three-dimensional likeness of theanatomical structure includes muscles.
 169. The injection trainingsystem of claim 161, wherein the three-dimensional likeness of theanatomical structure comprises arteries, veins, nerves, and skeletalportions that are to be avoided or accommodated during an injection.170. The injection training system of claim 161, wherein the one or morelayers of the anatomical structures are labeled.
 171. The injectiontraining system of claim 161, wherein different layers of the one ormore layers of the anatomical structures are displayed with differentcolors, different textures, or both.
 172. The injection training systemof claim 161, further comprising an injection tool, the injection toolcomprising a three-dimensional position sensor, the three-dimensionalposition sensor in communication with the signal processing and displayinterface.
 173. The injection training system of claim 172, wherein thesignal processing and display interface is configured to mapthree-dimensional position information of the three-dimensional positionsensor to the three-dimensional likeness of the anatomical structure onthe display device.
 174. The injection training system of claim 161,wherein the display device is configured to display the one or morelayers of the anatomical structure being peeled back as a new layer ispenetrated during a training injection.
 175. An injection trainingsystem, the system comprising: a signal processing and display interfacecomprising one or more processors; and a display device in communicationwith the signal processing and display interface, the display deviceconfigured to visually display a three-dimensional likeness of ananatomical structure as a stereoscopic representation, wherein thedisplay device is configured to further display labels of one or morelayers of the anatomical structure.
 176. The injection training systemof claim 175, wherein the anatomical structure is an injection site.177. The injection training system of claim 175, wherein differentlayers of the one or more layers of the anatomical structures aredisplayed with different colors, different textures, or both.
 178. Theinjection training system of claim 175, wherein the signal processingand display interface is configured to retrieve one or more models ofphysiological information from a database.
 179. The injection trainingsystem of claim 178, wherein the one or more models includethree-dimensional information indicating location(s) of certainanatomical or physiological features of the anatomical structure. 180.The injection training system of claim 175, wherein thethree-dimensional likeness of the anatomical structure on the displaydevice is configured to be displayed with a plurality of differentviews.
 181. The injection training system of claim 175, wherein theplurality of different views comprise rotated, zoomed in, zoomed out,cross-sectional, or time-lapsed views.